A seriously ill patient will often develop problems with their heart and circulation. These problems may be due to disease of the heart itself or be secondary to other disease. Problems seen may include: changes in volume and distribution of body fluid, changes in the condition of blood vessels and changes in the ability of the heart to pump blood around the body. Treatments for these problems may include the administration of fluid and/or the use of medicines that allow control of the heart rate, heart pumping function, volume of body fluid and blood pressure.

Breathing (or respiratory) problems occur if the breathing system is unable to provide enough oxygen to the tissues (hypoxia) or remove enough carbon dioxide from the body. Treatment is aimed at treating the underlying cause as well as correcting, where possible, low oxygen levels and the build-up of carbon dioxide. Mechanical support of the breathing system may be required to do so. Mechanical Ventilation (Ventilator) A ventilator is a breathing machine that is used to do the breathing for a patient with respiratory failure. It pumps air, and thereby provides oxygen, directly into the airways and lungs via a plastic breathing tube. This tube is inserted through the mouth and into the windpipe (trachea) under a short anaesthetic. Drugs are given to the patient to make them sleepy and to relax their muscles during the anaesthetic. In many patients, the breathing tube and machine are only required for a number of hours or days. Both tube and machine are removed when the patient’s breathing function normalises. However in some patients, breathing assistance is required for a prolonged period of time. The breathing tube is then usually shifted to the neck to make it more comfortable for the patient. This is done via an opening made into the windpipe (tracheostomy) under another short anaesthetic. Noninvasive Positive Pressure Ventilation Breathing support can also be delivered via a tight-fitting facemask or a special hood, without the need for a breathing tube. This can be done only under certain circumstances and with certain patients.

In a patient with kidney (renal) failure, the kidneys are unable to remove wastes and excess fluid from the body. This often occurs as a complication of other illnesses. Usually, more than one factor is present that contributes to its development. Kidney failure can occur suddenly (acute) or over a long time (chronic). If kidney failure is severe enough, a dialysis machine may be required to replace the function of the kidneys. When kidney failure is acute, treatment of the underlying illness usually enables the kidneys to start working again. However, if damage to the patient's kidneys has been present/worsening over a long time (chronic renal failure), the kidneys may not get better and life-long dialysis may be required.

Intravenous and intra-arterial lines (tubes inserted into veins and arteries) are often used to allow better monitoring of the patient, repeated pain-free blood testing and delivery of special medications. They are usually inserted when the patient is first admitted to Intensive Care. Visitors may be asked to wait in the waiting room until these procedures are finished.

A nasogastric tube is a tube inserted into the stomach through the nose. It is usually inserted at the same time as a breathing tube but may be inserted separately. The tube allows drainage of air and secretions from the stomach as well as allowing the patient to receive nutrition.